Dynamical fidelity susceptibility of decoherence-free subspaces
arXiv:1809.01261 · doi:10.1103/PhysRevA.99.062340
Abstract
In idealized models of a quantum register and its environment, quantum information can be stored indefinitely by encoding it into a decoherence-free subspace (DFS). Nevertheless, perturbations to the idealized register-environment coupling will cause decoherence in any realistic setting. Expanding a measure for state preservation, the dynamical fidelity, in powers of the strength of the perturbations, we prove stability to linear order is a generic property of quantum state evolution. The effect of noise perturbation is quantified by a concise expression for the strength of the quadratic, leading order, which we define as the dynamical fidelity susceptibility of DFSs. Under the physical restriction that noise acts on the register -locally, this susceptibility is bounded from above by a polynomial in the system size. These general results are illustrated by two physically relevant examples. Knowledge of the susceptibility can be used to increase coherence times of future quantum computers.
arXiv comment10 pages, 0 figures, corrected typos, section added, changed notation
References in corpus (29)
- Decoherence, einselection, and the quantum origins of the classical
- Quantum-enhanced measurements: beating the standard quantum limit
- Cavity quantum electrodynamics for superconducting electrical circuits: an architecture for quantum computation
- Decoherence Free Subspaces for Quantum Computation
- Noiseless Quantum Codes
- 14-qubit entanglement: creation and coherence
- Quantum Computers and Dissipation
- Bulk Locality and Quantum Error Correction in AdS/CFT
- Dynamics of Loschmidt echoes and fidelity decay
- Maintaining coherence in Quantum Computers
- Fidelity approach to quantum phase transitions
- Preserving coherence in quantum computation by pairing quantum bits
- Fidelity, dynamic structure factor, and susceptibility in critical phenomena
- Theory of Decoherence-Free Fault-Tolerant Universal Quantum Computation
- Decoherence-Free Subspaces and Subsystems
- A Unified and Generalized Approach to Quantum Error Correction
- Concatenating Decoherence Free Subspaces with Quantum Error Correcting Codes
- Quantum Error Correction
- Quantum Computation vs. Firewalls
- Robustness of Decoherence-Free Subspaces for Quantum Computation
- Error Avoiding Quantum Codes
- Geometry and response of Lindbladians
- Dissipation and Decoherence in a Quantum Register
- Information preserving structures: A general framework for quantum zero-error information
- Dynamical phase transitions at finite temperature from fidelity and interferometric Loschmidt echo induced metrics
- Limitation of entanglement due to spatial qubit separation
- Geometry, robustness, and emerging unitarity in dissipation-projected dynamics
- Scalable fault-tolerant quantum computation in DFS blocks
- Universality of Black Hole Quantum Computing